Self-incompatibility is a device to prevent inbreeding. It is a:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Genetic mechanism
Explanation: The third device to prevent inbreeding is self-incompatibility. This is a genetic mechanism.
What guides the pollen tube into the synergid?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: The Filiform Apparatus
Explanation: Filiform apparatus present at the micropylar part of the synergids guides the entry of pollen tube.
Bagging of the emasculated flower is done to:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Prevent contamination by unwanted pollen
Explanation: Emasculated flowers have to be covered with a bag... to prevent contamination of its stigma with unwanted pollen.
The fusion of the male gamete with the egg cell is called:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Syngamy
Explanation: One of the male gametes moves towards the egg cell and fuses with its nucleus thus completing the syngamy.
Which of the following statements about the Primary Endosperm Nucleus (PEN) is correct?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: It is triploid and formed by triple fusion.
Explanation: The other male gamete moves towards the two polar nuclei... and fuses with them to produce a triploid primary endosperm nucleus (PEN).
Which part of the embryo is located above the level of attachment of the scutellum in monocots?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Epicotyl
Explanation: The portion of the embryonal axis above the level of attachment of scutellum is the epicotyl.
In the seed, the micropyle facilitates the entry of:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Oxygen and water
Explanation: The micropyle remains as a small pore in the seed coat. This facilitates entry of oxygen and water into the seed during germination.
Which of the following records refers to a seed that germinated after 2000 years?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Phoenix dactylifera
Explanation: A recent record of 2000 years old viable seed is of the date palm, Phoenix dactylifera.
Hybrid seeds lose their value if the progeny:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: A
Answer: Segregate characters
Explanation: If the seeds collected from hybrids are sown, the plants in the progeny will segregate and do not maintain hybrid characters.
Who popularized the use of embryological characters in taxonomy?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: A
Answer: Panchanan Maheshwari
Explanation: He worked on embryological aspects and popularised the use of embryological characters in taxonomy.